1- edit your site's ....place the following code:
https://github.com/alidz1982/Slide-Out-Footer/blob/master/Header%20Code.php
2-On top of the header code is the footer code box. Now insert the following HTML code in the footer code box:
https://github.com/alidz1982/Slide-Out-Footer/blob/master/footer%20code%20box.php